A Study of Suvorexant (MK-4305) for the Treatment of Insomnia Disorder in Participants With Opioid Use Disorder (MK-4305-098)

A Phase 3, Multicenter, Randomized, Double-blind, Placebo-controlled Study to Evaluate the Efficacy and Safety of Suvorexant for the Treatment of Insomnia in Participants With Opioid Use Disorder

People with opioid use disorder (OUD) can have trouble falling or staying asleep. Researchers want to know if suvorexant will help people with OUD fall asleep and stay asleep. The goal of this study is to learn about the safety of suvorexant and how well people tolerate it. Researchers also want to learn if suvorexant helps people sleep longer compared to people who take placebo. A placebo looks like the study medicine but has no actual study medicine in it.

Study Overview

• Status: Recruiting
• Conditions: Insomnia
• Intervention / Treatment: Drug: Placebo; Drug: Suvorexant

• Study Type: Interventional
• Enrollment (Estimated): 300
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Toll Free Number; Phone Number: 1-888-577-8839; Email: Trialsites@msd.com

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06520
      • Recruiting
      • Yale University School of Medicine ( Site 1003)
      • Contact: Study Coordinator; Phone Number: 203-785-3627
  • Georgia
    • Savannah, Georgia, United States, 31405
      • Recruiting
      • CenExel iResearch, LLC ( Site 2010)
      • Contact: Study Coordinator; Phone Number: 912-744-0800
  • Maryland
    • Baltimore, Maryland, United States, 21224
      • Recruiting
      • Johns Hopkins University ( Site 1001)
      • Contact: Study Coordinator; Phone Number: 443-216-9237
  • New Jersey
    • Marlton, New Jersey, United States, 08053
      • Recruiting
      • Hassman Research Institute Marlton Site ( Site 2005)
      • Contact: Study Coordinator; Phone Number: 856-261-6420
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73112
      • Recruiting
      • The Rivus Wellness & Research Institute ( Site 2014)
      • Contact: Study Coordinator; Phone Number: 405-607-2233
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Recruiting
      • Penn Medicine University of Pennsylvania Health System- Center for Studies of Addiction ( Site 1006)
      • Contact: Study Coordinator; Phone Number: 215-222-3200
  • Rhode Island
    • Providence, Rhode Island, United States, 02906
      • Recruiting
      • Butler Hospital ( Site 1002)
      • Contact: Study Coordinator; Phone Number: 401-455-6440
  • South Carolina
    • Charleston, South Carolina, United States, 29403
      • Recruiting
      • Medical University of South Carolina ( Site 1005)
      • Contact: Study Coordinator; Phone Number: 843-792-4636
  • Texas
    • DeSoto, Texas, United States, 75115
      • Recruiting
      • Adams Clinical Dallas ( Site 2007)
      • Contact: Study Coordinator; Phone Number: 972-283-6286
    • Houston, Texas, United States, 77043
      • Recruiting
      • Memorial Hermann Village ( Site 2001)
      • Contact: Study Coordinator; Phone Number: 281-369-5765
  • Virginia
    • Richmond, Virginia, United States, 23219
      • Recruiting
      • VCU Institute for Drug and Alcohol Studies ( Site 1004)
      • Contact: Study Coordinator; Phone Number: 804-827-3784

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Has a primary diagnosis of OUD according to Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5), and confirmed through the Mini International Neuropsychiatric Interview (MINI).
• Is on a verified, stable dose of medications for opioid use disorder (MOUD) treatment.
• Meets DSM-5 criteria for the diagnosis of Insomnia Disorder
• Has a regular bedtime between 8 PM (20:00) and 1 AM (01:00) and is willing to maintain it for the duration of the study.
• Has not used opioids for a period of at least 4 weeks before entering the study.

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Has current uncontrolled major co-morbid psychiatric illness including major depressive disorder, bipolar disorder, schizophrenia, or any psychiatric condition with psychotic features.
• Has current diagnosis or history within 5 years of any of the following: narcolepsy, sleep paralysis, severe periodic limb movement disorder, restless leg syndrome, cataplexy, circadian rhythm sleep disorder, parasomnia including nightmare disorder, sleep terror disorder, sleepwalking disorder, rapid eye movement (REM) behavior disorder, significant degree of sleep-related breathing disorder, excessive daytime sleepiness (EDS), or primary hypersomnia.
• Is at imminent risk of self-harm.
• Has a known history of stroke that may confound the diagnosis of insomnia.
• Has a clinically significant movement disorder such as akinesia.
• Has a history of hepatitis or live disease.
• Has habitual use of central nervous system (CNS)-depressants or stimulants that may be responsible for the participant's disturbed sleep.
• Has a history of malignancy, ≤3 years prior to start of study, with the exception of nonmelanoma skin cancer, prostate cancer or localized carcinoma in situ of the cervix.
• Has a history of hypersensitivity to more than 3 chemical classes of drugs, including prescription and over-the-counter medications.
• Has donated blood products or had phlebotomy within 8 weeks prior to start of study.
• Has a history of transmeridian travel within 2 weeks prior to start of study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Suvorexant; Participants receive 10 mg of suvorexant for the first three nights, increased to 20 mg of suvorexant nightly thereafter at the investigator's discretion, for up to approximately 8 weeks.	Drug: Suvorexant; Oral Tablet; Other Names: MK-4305
Placebo Comparator: Placebo; Participants receive suvorexant-matching placebo for up to approximately 8 weeks.	Drug: Placebo; Oral Tablet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in Total Sleep Time at Week 8	Total sleep time will be measured in a sleep laboratory by polysomnography at the participant's habitual bedtime. Change from baseline in total sleep time at Week 8 will be reported.	Baseline and Week 8
Number of Participants Who Experience One or More Adverse Events (AEs)	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.	Up to approximately 10 weeks
Number of Participants Who Experience One or More Serious Adverse Events (SAEs)	An SAE is any untoward medical occurrence that at any dose results in death, is life threatening, requires or prolongs inpatient hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly or birth defect or is another important medical event deemed such by medical or scientific judgement.	Up to approximately 10 weeks
Number of Participants Who Discontinue Study Treatment Due to an AE	An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.	Up to approximately 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from Baseline in Wakefulness after Persistent Sleep Onset at Week 8	Wakefulness after persistent sleep onset will be measured in a sleep laboratory by polysomnography at the participant's habitual bedtime. Change from baseline in wakefulness after persistent sleep onset at Week 8 will be reported.	Baseline and Week 8
Number of Participants Who are Positive for Substance Abuse at Day 1	A positive assessment for substance abuse at Day 1 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.	Day 1
Number of Participants Who are Positive for Substance Abuse at Day 4	A positive assessment for substance abuse at Day 4 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.	Day 4
Number of Participants Who are Positive for Substance Abuse at Week 2	A positive assessment for substance abuse at Week 2 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.	Week 2
Number of Participants Who are Positive for Substance Abuse at Week 4	A positive assessment for substance abuse at Week 4 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.	Week 4
Number of Participants Who are Positive for Substance Abuse at Week 8	A positive assessment for substance abuse at Week 8 is defined as either a positive urine drug test for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis OR a positive response on the Substance Use History (SUH) Since Last Assessment questionnaire. The Substance Use History Questionnaire (SUH) has been developed specifically for this study. This is a self-reported questionnaire used to obtain a variety of quantitative estimates of cannabis, alcohol, and other nonmedical substance use. The SUH Since Last Assessment Questionnaire will be used to assess nonmedical substance and alcohol use since the previous study visit.	Week 8
Number of Participants with Positive Urine Drug Screen	A positive urine drug screen is defined as urine drug test positive for opioids and other nonmedical substances including fentanyl, cocaine, amphetamines, benzodiazepines, and cannabis	Day 1, Day 4, Week 2, Week 4, Week 8

Collaborators and Investigators

• Sponsor: Merck Sharp & Dohme LLC
• Investigators: Study Director: Medical Director, Merck Sharp & Dohme LLC

Publications and helpful links

Helpful Links

• Merck Clinical Trials Information

Study record dates

Study Major Dates

• Study Start (Actual): October 9, 2025
• Primary Completion (Estimated): June 24, 2027
• Study Completion (Estimated): June 24, 2027

Study Registration Dates

• First Submitted: October 22, 2024
• First Submitted That Met QC Criteria: October 22, 2024
• First Posted (Actual): October 24, 2024

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Initiation and Maintenance Disorders; Sleep Aids, Pharmaceutical; Orexin Receptor Antagonists; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Neurotransmitter Agents; Hypnotics and Sedatives; suvorexant
• Other Study ID Numbers: 4305-098; MK-4305-098 (Other Identifier: MSD)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No